One Minute Mentor: Mechanical Shock

Mechanical shock is sometimes used to stabilize tool steels. One method of producing shock is to suspend the part so that it hangs freely and then strike it with a wooden hammer. This is believed to set up elastic waves which add to the magnitude of the residual stress imparted by the previous heat treatment. At locations where the resultant magnitude of stress exceeds the elastic limit, plastic flow should occur and result in stress relief. This would be manifest by higher dimensional stability. A shock treatment should not be considered as a substitute for a thermal method of stabilization but rather as an auxiliary method which enhances stabilization.

Dimensional changes in W1 steel resulting from dropping on a concrete floor as determined by Fletcher (are shown in Fig. 6. The untempered specimens showed greater dimensional changes than the tempered specimens due to the higher level of residual stress in the untempered condition.

For more information, click on the link below (subscription required). Then scroll to Figure 6.

Jon L. Dossett; George E. Totten, *Control of Distortion in Tool Steels*, ASM International, 2014
https://doi.org/10.31399/asm.hb.v04d.9781627081689

Kanthal wins e-prize for industrial heating electrification

Kanthal, Amherst, NY, announced that it has been awarded the prestigious E-prize in the energy optimization category for its innovative technology supporting fossil-free industrial production. Organized by Sweden’s leading business newspaper Dagens Industri, Aktuell Hållbarhet, and the energy group E.ON, the E-prize recognizes groundbreaking advancements in energy innovation. This marks the 16th year the award has celebrated industry-leading solutions.

The jury highlighted Kanthal’s ability to combine a 90-year-old invention with modern innovation to replace natural gas with electric heating in high-temperature industrial processes. This transition enables fossil-free production, reducing emissions and improving working conditions. Kanthal was recognized as a global pioneer in sustainable industrial electrification, with applications ranging from steel production to manufacturing solar cells and batteries.

Robert Ståhl, president of Kanthal, noted the significance of the award, stating that the company’s technology allows industries such as steel, batteries, semiconductors, and glass to reduce emissions by transitioning to electricity for industrial heating. Nicolai Schaaf, sustainability manager at Kanthal, added that electrification not only reduces emissions but also supports the broader expansion of fossil-free energy management.

Kanthal’s technology, rooted in a 93-year-old innovation, is designed to electrify high-temperature processes across industries, eliminating CO2 emissions when powered by fossil-free electricity. These processes, integral to manufacturing sectors such as steel, aluminum, glass, and cement, account for a significant share of global industrial CO2 emissions, making Kanthal’s solutions critical for sustainable industrial transformation.

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One Minute Mentor: Improving the Homogeneity of the Distortion Behavior

Controlling out-of-roundness is important for certain precision applications, such as class C and D cutting hobs made of high-speed steels. Class C and D hobs must be held close to size limits because they are not ground to size after heat treatment, but rather are used in the unground condition.

Normal size distortion in hardening and tempering can be accommodated by making the tool slightly oversize or slightly undersize, as required, before heat treating. High-speed steel bars, however, have been observed to go out-of-round as much as 0.05 mm (0.002 in.) during heat treatment. The pattern of size distortion shown in Fig. 8 can occur. It appears to be related to the initial shape of the cast ingot and to the specific primary-mill processing used to reduce the ingot into bars.

For more information, click on the link below (subscription required). Then scroll to Figure 8. R Schneider; R. Mesquita; W Schützenhöfer, Distortion in Tool Steels, ASM International, 2014  https://doi.org/10.31399/asm.hb.v04d.a0005980

Wisconsin Oven ships small batch oven to Canadian manufacturer

Wisconsin Oven, East Troy, WI, announced the international shipment of an electrically heated small batch oven to a Canadian manufacturer of automotive components. The oven, designed for curing parts, has a maximum temperature rating of 650°F and chamber dimensions of 4’ W x 4’ L x 4’ H. Prior to shipment, the oven’s temperature uniformity of ± 10°F was verified through a nine-point profile test conducted in an empty chamber under static conditions.

The unit features patented high-efficiency panel seams for improved insulation, a 4” thick insulated floor, and two carbon steel shelves for part loading, each rated for 5 pounds per square foot. It utilizes combination airflow for optimal heating rates and uniformity, with temperature controlled by a Watlow F4T digital controller, featuring a touch screen, PID control, and Ethernet communication.

The oven also includes a process timer with an audible alarm, ensuring consistent curing and part quality.

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One Minute Mentor: Process Control in Nitriding Systems

Modern gas nitriding and nitrocarburizing furnaces are equipped with sensor systems and a process control unit that allow the measurement and automatic control of the nitriding potential (KN). The figure shows an example of how the process control can be carried out. 

Defined amounts of ammonia, nitrogen, and—for nitrocarburizing processes—carbon dioxide, can be chosen for each step in the program and fed into the furnace via mass flow controllers. The gas composition in the retort is measured via a nitriding probe. For the measurement of nitrocarburizing processes two different probes are needed. The control unit calculates the nitriding potential according to the measured values and controls the mass flow of ammonia to meet the requested set point of KN. During the nitriding process the gasifying amount of ammonia can just be reduced to a certain limit. To keep the KN value low, therefore, precracked ammonia must be added. It must be mentioned that there are some more simple control systems available, which also produce good results.

For more information, click on the link below (subscription required). Then scroll to Figure 25. R Schneider; R. Mesquita; W Schützenhöfer, Distortion in Tool Steels, ASM International, 2014  https://doi.org/10.31399/asm.hb.v04d.a0005958

One Minute Mentor: Salt Bath Nitrocarburizing Equipment

Modern salt bath nitrocarburizing units can be arranged as fully automated and contained lines and usually consist of an air-preheating furnace, one or several salt bath nitrocarburizing furnaces, which can either be heated electrically or by gas combustion, and a cooling unit that can be an oxidizing salt bath. Such oxidizing posttreatment builds up a thin and dense oxide layer on top of the compound layer that significantly increases the corrosion resistance. 

Online monitoring of the chemical composition is not required due to the high stability of the melt and the automatic supply of refill salt and regenerators. The nitrocarburizing line usually ends with three- to four-step washing cascades that also act as a regeneration system for the salt.

Gas nitriding and nitrocarburizing is the most sensitive process regarding passivation effects typical for medium- to high-alloy tool steels. Therefore special attention must be paid to cleaning and pretreatment processes such as preoxidation, controlled oxinitriding, or the use of chemicals such as hydrazine. On the other hand, gas processes have the best accessibility for boreholes and thin gaps.

For more information, click on the link below (subscription required). Then scroll to Figure 21. R Schneider; R. Mesquita; W Schützenhöfer, Distortion in Tool Steels, ASM International, 2014  https://doi.org/10.31399/asm.hb.v04d.a0005958

 

Researchers overcome manufacturing challenges in aluminum alloys with nano-treatment

Researchers at the University of California, Los Angeles, have achieved a significant breakthrough in the field of metal additive manufacturing (AM), specifically with Al–Cu alloys like AA2024, which are prevalent in the aerospace and automotive industries. 

These alloys are known for their high strength and good fatigue resistance but have been notoriously difficult to work with in additive manufacturing due to issues like hot cracking and other solidification defects.

The UCLA team has successfully developed a nano-treated AA2024 deposition that incorporates TiC nanoparticles, leading to a groundbreaking enhancement in the manufacturing process. This new method allows for the additive manufacturing of AA2024 without the occurrence of cracks, a common issue that has hindered broader adoption of these materials in high-precision sectors.

Microstructural analysis conducted by the researchers reveals that the TiC nanoparticles not only reduce the susceptibility to hot cracking but also refine and homogenize the grain structure of the alloy. The grains were significantly refined to an average size of 23.2 ± 0.4 μm. This refinement contributes to the material’s enhanced properties, including its mechanical performance.

These findings highlight the potential of nano-treatment techniques in overcoming the longstanding challenges associated with high-strength aluminum in additive manufacturing. This advancement not only paves the way for more reliable production of critical components in aerospace and automotive applications but also promises to expand the capabilities and applications of metal additive manufacturing technology.

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Solar Atmospheres acquires Certified Metal Craft Inc.

Solar Atmospheres, El Cajon, CA, , has announced the acquisition of Certified Metal Craft (CMC) based in El Cajon, California. This move marks Solar Atmospheres’ sixth nationwide location and enhances its presence on the West Coast.

Founded nearly 55 years ago, CMC has been a reputable and trusted service provider in the Southern California region, specializing in various heat treating processes including Vacuum, Aluminum, Atmospheric, Endothermic, Salt Bath, and Cryogenic processing. The company’s dedication to quality has earned it a Nadcap accreditation and a robust portfolio of customer and prime approvals in the Aerospace, Medical, and Commercial sectors.

This expansion not only solidifies Solar Atmospheres’ commitment to providing top-notch heat treating and brazing solutions but also underscores its industry-leading approach of integrity and honesty in all business dealings. The integration promises to bolster Solar’s operational capabilities and enhance its service offerings across the West Coast, ensuring that the company remains the “go-to” choice for clients in the sector.

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